The present invention relates to modular ceramic fiber insulation systems and more particularly to the components of a modular system in which the insulation modules are easily and securely installed simply by forcing them into interlocking engagement with a complementary clip that has been previously secured to an interior surface of a furnace.
Modular systems for insulation of furnaces, kilns and the like are not of themselves novel. Many different modular systems in which modules formed in part of ceramic fiber blanket or mat are employed have been proposed. Many of these have been successfully employed and enjoy great commercial success. However there remains a need for a ceramic fiber modular insulation system or furnace lining which can be easily and rapidly installed with minimum usage of special tools by a labor force not having highly specialized skills in which each module remains installed until it is necessary to replace that module due to damage or wear out. It is of course desired to meet these objectives in as economical a manner as possible, the total economy of a system necessarily taking into account the cost of the component materials and subassemblies and the cost of labor to manufacture and install the lining and the insulating effectiveness and life of the resulting installation.
Examples of known modular ceramic fiber insulation systems include the following:
U.S. Pat. No. 3,940,244 to Sauder et al. discloses an insulation module for lining an interior wall of a high temperature chamber comprising first and second blocks of high temperature insulating material each of said first and second blocks comprising a plurality of strips of resilient fiber insulation positioned adjacent to each other in side-by-side relation with the fibers of said resilient strips being arranged in planes substantially perpendicular to the plane of said respective relatively hot faces, the module including a backing sheet of a material such as expanded metal having openings throughout which engage with a configured arcuate washer and a stud to retain the module securely to the furnace wall. The washer is sized and configured such that its in-prongs will lock into place onto one diamond of the expanded metal backing. The modules described in this patent may also be attached by a stud welding technique more fully described in U.S. Pat. No. 3,706,870 to Robert A. Sauder et al. Alternatively, when the open mesh type backing plate is employed, an explosive impact type dry pin fastener technique may also be employed to fasten the module to the furnace wall.
U.S. Pat. No. 3,832,815 to Balaz et al. discloses ceramic fiber insulation for lining furnaces in which the insulation fibers are formed into prefabricated modules by compression members located at the outer cold side end portion of the insulation layer and by which the modules are mounted in position of use on the furnace wall. Each module is fabricated of layers of high temperature ceramic fiber blanket material which are disposed substantially perpendicular to the hot face of the furnace lining. The layers are compressed during assembly into a resilient bundle. The compression forces inside each module are resisted by pins threaded substantially perpendicularly through the blanket layers and disposed near the outer cooler face of the module that is remote from the interior of the furnace. The retainer members comprise elongated strips of expanded metal having a length corresponding to the width of the assembled strips and are formed to be L-shape in cross-section. These retainer members are secured to the furnace wall, for example, by a plurality of pins which extend through the furnace exterior shell. The base portion of the retainer members are deemed to be not essential.
U.S. Pat. No. 3,952,470 to Byrd, Jr. disloses a modular ceramic fiber insulation wherein a folded insulating blanket of refractory fibrous material is provided with a support mounted lengthwise and imbedded within a fold in the blanket to support the blanket, and a mounting means which includes suspension arm which extends through the folds of the blanket from the support beam to an attachment beam for mounting with the wall of the furnace, the attachment beam having openings formed therein for passage of connecting members therethrough to attach the attachment beam to the wall of the furnace. The main support beam is attached to the furnace wall in conventional manner, i.e. by welding or the use of screws, bolts and the like.
U.S. Pat. No. 4,339,902 to Cimochowski et al. discloses a modular thermal insulation device formed of folded fibrous insulating blanket and a metallic attachment structure adapted to be secured to a wall of a furnace, kiln or like structure. A bar is imbedded in a fold of the blanket. The bar is attached by a connecter to the main beam is in the form of a C-shaped channel which is mounted to a furnace wall by first placing a flanged mounting clip against the furnace wall and then sliding the C-shaped attachment means over the clip so the flanges of the beam engage the flanges of the mounting clip.
U.S. Pat. No. 4,381,634 to Hounsel et al. discloses the refractory ceramic fiber blanket module having a continuous strip of ceramic fiber folded into a number of layers in serpentine fashion. Certain of the folds contain support rods which engage a perpendicularly extending support rod which is inserted through the suspension tabs of a slide channel member which has a C-shaped cross-sectional configuration. The C-shaped slide channel engages a complementary attachment member that has been previously stud welded or otherwise attached to the inner surface of the furnace.
U.S. Pat. No. 4,120,641 to Myles discloses a ceramic fiber module which comprises a weldable (metallic or perforate refractory) backing and a number of ceramic fiber mats cemented to the backing by the edge of the mat so as to leave a portion of the backing accessible between mats or on their perimeter for welding. The weldable backing is welded to a metallic substrate preferably by use of spherical attachments.
U.S. Pat. No. 4,287,839 to Severin et al describes an apparatus for lining the inner walls of industrial furnaces with a plurality of insulating blocks, each block comprising an insulating mat which is folded in corrugated matter, the insulating mats being made of highly resistant material such as ceramic fibrous material. Each insulating mat is penetrated below the extreme ends of the folds by carrying bars which are affixed to lugs which are in turn joined to a base plate having on opposite sides webs that are bent outwards. The webs have holes for the purpose of joining adjacent insulating blocks by means of bolts. Also suspension hooks are attached to the base plate in a rotatable manner. The suspension hooks are hooked into or suspended from holding bars which are themselves suspended from U-shaped beams, e.g. beams of a furnace roof. This system permits replacement of individual defective insulating blocks from outside the furnace without interrupting its operation. The carrying bars penetrate the ceramic fiber mat layers substantially perpendicular to the planer faces of the ceramic fiber mat.
U.S. Pat. No. 4,324,602 to Davis et al describes the installation of thermal insulation modules in which the modules are affixed to the furnace wall by a chemical adhesive.